1. Field of the Invention
This invention relates to a portable prosthetic device used to treat a human joint by applying "continuous passive motion".
2. Description of the Prior Art
Dr. Robert B. Salter, Professor and Head of Orthopaedic Surgery at the University of Toronto, and Senior Orthopaedic Surgeon at the Hospital for Sick Children in Toronto, first developed the concept and coined the expression "continuous passive motion". Dr. Salter's work is described in the article "Joints Were Meant to Move--And Move Again" by Ohlendorf in "The Graduate", published by The Department of Information Services, University of Toronto, September/October 1980.
Briefly, according to this concept, a human joint, for example, a knee, elbow, or finger joint, is kept under slow continuous constrained motion as distinct from being held motionless or being moved intermittently. Keeping an injured or post operative joint mobile rather than immobilizing it in a cast is beneficial to the cartilage.
Attempts which have been made to provide machines that exercise joints are designed for intermittent operation and do not supply continuous passive motion. Moreover, they are usually too heavy and bulky to be readily portable and thus to be mounted on the body.
A primary aim of the present invention is to provide an apparatus which imparts continuous motion to the joint and which is portable so that it can be mounted on the patient's body.